Sheet limiter

ABSTRACT

A sheet-feed control mechanism limits the flow of original sheets manually inserted into a copy machine. The control mechanism comprises a stationary shoulder surface and a movable stop positioned on opposite sides of a sheet entrance path. The movable stop is selectively movable into the sheet entrance path to direct leading edges of newly inserted sheets against the shoulder surface while allowing a previously inserted sheet to continue to move beyond the shoulder surface. An original sheet sensor and a stop motivating solenoid move the stop into and out of the sheet entrance path at appropriate times.

United States Patent Alderman, Jr. et a].

l l June 10, 1975 Walsh Til/235 Dummeier Bi l/227 [57 ABSTRACT A sheet-feed control mechanism limits the flow of original sheets manually inserted into a copy machine. The control mechanism comprises a stationary shoul- Cler surface and a movable stop positioned on opposite sides of a sheet entrance path. The movable stop is selectively movable into the sheet entrance path to direct leading edges of newly inserted sheets against the shoulder surface while allowing a previously inserted sheet to continue to move beyond the shoulder surface. An original sheet sensor and a stop motivating solenoid move the stop into and out of the sheet en trance path at appropriate times.

l l SHEETLIMITE'LR l7i Inventors: Albert D. Alderman. Jr.. Skippack;

(iahriel B. Cherian, York, hoth of Pa.

173] Assignee: Sperry Rand Corporation. New

York, NYv

[22] Filed; May 23, I974 [21] Appl. No: 472.743

151} U.S.Cl ..271/8 R;27l/3;27l/245; 27l/258 {51] Int. Cl B65h 5/00; BoSh 7/20 c 8] Field of Search 27l/3, 227. 229. 237, 245. 271/246. 247. 265. 264226131167. 12], 8. 256. 258, 266. 230, 236

|56| References Cited UNITED STATES PATENTS 2,638,344 5/l953 Hayes Z7l/245 X K m a: 6/

2;: lia-d us IP23 My SHEET LIMI'I'ER BACKGRUI NI) ()F llll l.\\ IN'I ION This invention relates broadly to the art of sheet feeding and more specifically to sheerl'eed control apparatus which serve to regulate the insertion of sheets into sheet processing machines.

Some copy machines can recei\e and copy original documents at unusually fast rates. In this regard. at least one copy machine. (described in copending application Ser. No. 327.405 filed Jan. 29. I973. now US. Pat. No. 3.834.805 entitled Xerographic (opier with Asynchronous Copy] is ready to receive a subsequent original document for copying almost as soon as a previously inserted original document has fully entered the copy machine. A problem arises however in that an operator who is inserting original copies into the machine. one after the other. may overlap the original doeu ments. if he is inserting too rapidly. or leave an undue amount of space between thetn. if he is not inserting rapidly enough. The former situation leads to malfunctions of the machine and the latter situation wastes time.

Thus. it is an object of this invention to provide a sheet-control mechanism which limits the insertion of sheets to a sheet processing device so that they do not overlap. but yet which allows following sheets to be inserted into the sheet processing device as soon as it is prepared to receive them.

It is another object of this invention to provide a reliable sheet flow regulating device which can be momentarily opened to allow a leading edge of a sheet to pass. but which can thereafter be closed to prevent further sheets from passing while continuing to allow the first sheet to pass.

SUMMARY OF THE INVENTION According to principles of this invention. a shoulder surface and a movable stop are positioned on opposite sides of a sheet entrance path of a copy machine. When the movable stop is moved into the sheet entrance path, it directs the leading edges of sheets thereafter inserted into the sheet entrance path against the shoulder surface; however. it allows sheets which were previously inserted into the sheet entrance path to pass the shoulder surface. A sensor and stop motivator selectively move the stop out of the sheet entrance path when the copy machine is prepared to receive a sheet and into the sheet entrance path when a sheet leading edge is beyond the shoulder surface.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects. features and advantages ofthe invention will be apparent from the following more particular description of a preferred embodiment of the invention. as illustrated in the accompanying drawings in which reference characters refer to the same part throughout the different views. The drawings are not necessarily to scale. emphasis instead being placed upon illustrating principles of the invention in a clear manner.

FIG. I is a sectional view ofa copy machine including a sheet-feed control mechanism employing principles of this invention;

HG. 2 is a view taken on line 2-2 of FIG. 1;

FIG. 3 is an isometric view of a portion of the sheetfeed control mechanism of FIGS. l and 2'. and

(all

FIGS. 4 and 5 are sectional views ofa sheeH'eed con trol mechanism employing principles of this invention in two modes of operation.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1. a copy machine ll receives original documents at an original entrance I3 and expels them from an exit onto an exit tray I7. The original documents are hand fed. one after the other. into the original entrance 13 until they are gripped by entrance rollers I). The entrance rollers 19 then feed the original documents past a window 2] to exit drive rollers 23. In this regard. the original documents are scanned at the window 2] for the purpose of making copies thereof; however. it is not thought necessary to go into greater detail of the copy machine I] inasmuch as it is not a major part of this invention.

A sheet feed control mechanism. designated generally by numeral 25. limits the insertion oforiginal documerits through the original entrance 13, along a sheet entrance path 14, to the nip 27 of the entrance drive rollers 19. This mechanism prevents original documents from overlapping but allows original documents to be fed to the copying machine 1] at an optimized rate.

The sheet-feed control mechanism comprises an original top guide 29 (defining a notch 31}. a stop assembly 33. a solenoid 35, and a sheet sensor 37.

The original top guide 29 complements an original bottom guide 39 and a frame element 40 to help define the original entrance l3 and the sheet entrance path 14. The notch 31. with reference to FIG. 4. includes a laterally disposed shoulder 41 which faces the direction from which original documents are inserted into the original entrance 13. The notch 31 and the shoulder 41 are as long as the width of sheets handled by the copy machine 11.

The stop assembly 33 includes a stop plate 43 (FIG. 3) having individual stop elements 45 (1-1! extending laterally therefrom. The stop plate 32 is rigidly attached to a rotatable shaft 47. The rotatable shaft 47 is rotatably mounted on a copy machine frame 49 so that the stop elements 45 (1-11 can be rotated into the sheet path 14 at positions immediately adjacent the notch 3|. A spring lever 51 is also rigidly attached to the shaft 47. and a spring 53, extending between the end of the spring lever 51 and the copying machine frame 49, biases the stop elements 45 0-11 toward the notch 31 to the FIGS. 1 and 4 position.

A solenoid lever 55 is also rigidly attached to the shaft 47 and this lever is coupled to the solenoid 35. When the solenoid 35 is energized. an armature thereof 57 is pulled downwardly. as illustrated in FIG. 5 so that the stop elements 45 U([ are moved away from the notch 31 against the bias of the spring 53.

The sheet sensor 37 is positioned at the nip 27 of the entrance rollers 19 to detect the pressure of an original document at the entrance-roller nip 27. The sheet sensor 37 can have various forms; and. in the illustrated embodiment it is a microswitch which is actuated by contact with sheets at the nip 27. The sheet sensor 37 has the dual purpose of sensing when the leading edge of an original document has passed the shoulder 41 and when the copy machine II is ready to receive another original document. as will be further described below with reference to operation of the device.

The sheet sensor 37 is linked to the solenoid 35 via a power supply 59. ln this regard. it should be understood that the circuitry depicted in FIG. 1 is simplified for the purpose of clarity. In any event. when the sheet sensor 37 does not detect an original document at the roller nip 27. the power supply 59, in response thereto. energizes the solenoid 35 so that the stop elements 45 a-d are rotated away from the notch 31 out ofthc sheet entrance path. However. when the sheet sensor 37 senses the presence of an original document at the roller nip 27, the power supply 59 responds thereto by dcenergizing the solenoid 35. The spring 53 then rotates the stop elements 45 -11 into the sheet entrance path adjacent the notch 31.

In operation. when the copy machine II is first turned on. the sheet sensor 37 does not detect a sheet in the roller nip 27 so the power supply 59 energizes the solenoid 35 to rotate the stop elements 45 a-d away from the notch 31, out of the sheet entrance path. Thus. with reference to FIG. 5. an original sheet 61 which is manually inserted into the original entrance 13 is allowed to pass the notch 31 until its leading edge 63 is inserted into the nip 27 of the entrance rollers 19. The sheet sensor 37 senses this nip insertion and the power supply 59, in response thereto, deenergizes the solenoid 35 to allow the stop elements 45 a-d to move into the sheet entrance path toward the notch 31. as depicted in FIG. 4. Now when an operator inserts an additional original document 65, the stop elements 45 u-d. pressing on the first original document 6]. direct the leading edge of the additional original document 65 into the laterally displaced shoulder 41 of the notch 31. Thus. an operator is prevented from inserting the additional original document 65 into the nip 27 of the rollers 19. however. the first original document 6l can continue to be pulled into the copy machine ll by the entrance rollers 19.

When the following edge of the first original document 6] clears the nip 27 of the rollers 19, the copy machine ll is ready to receive the additional original document 65. The sheet sensor 37 senses when the first original document 6] has cleared the nip 27 and the power supply 59. in response thereto, energizes the solenoid 35 to rotate the stop elements 45 a-d out of the sheet entrance path. Thus, the stop elements 45 0-11 are no longer in position to direct the leading edge of the additional original document 65 against the laterally disposed shoulder 41'. so the leading edge of the additional original document 65, due to an inclined disposition of the shoulder surface 41, is allowed to drop into the sheet entrance path and the operator can feed it into the nip 27 of the rollers 19. The sheet sensor 37 senses such insertion and the cycle is repeated.

This invention tends to optimize the rate at which original documents can be fed to a copy machine while preventing overlap. or double. feeds.

While the invention has been particularly shown and described with reference to a preferred embodiment. it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention. For example. various types of sensors could serve as the sheet sensor 37. Further. the single sensor 37 could be replaced by several sensors. with one sensor being positioned closer to the laterally disposed shoulder 41 for detecting when a leading edge of a sheet has cleared the shoulder 4l quicker than in the described embodiment.

The embodiments of the invention is which an exclusive property or privilege are claimed are defined as follows:

1. A sheet-feed control mechanism to be used with a sheet processing apparatus which is designed to accept one sheet at a time and which cannot accept a subsequent sheet until a previous sheet has been processed to a predetermined degree. said sheet feed control mechanism comprising:

a guide means for defining a sheet entrance path and for guiding sheets inserted into said sheet processing apparatus along said sheet entrance path. said guide means defining a shoulder surface laterally disposed to said sheet entrance path and facing the direction from which sheets are inserted into said sheet entrance path;

a movable stop means positioned adjacent said sheet entrance path opposite said shoulder surface. said movable stop means being selectively movable into said sheet entrance path for directing the leading edges of sheets thereafter inserted into said sheet entrance path against said shoulder surface but for allowing a previously inserted sheet to continue to move beyond said shoulder surface. and movable out of said sheet entrance path for allowing sheets to pass said shoulder surface without the leading edge thereof being directed toward said shoulder surface;

a sensing means for sensing the position of sheets traveling along said sheet entrance path;

a motivating means coupled to said sensing means for selectively moving said stop means into and out of said sheet entrance path in response to said sensing means sensing the locations of said sheets.

2. A sheet-feed control mechanism as claimed in claim 1 wherein:

said sensing means is positioned downstream of said shoulder surface for sensing when a sheet has entered said sheet processing apparatus to a predetermined extent at which said sheet processing apparatus is prepared to receive an additional sheet and for sensing when the leading edge of a sheet is beyond said shoulder surface; and

said motivating means is for selectively moving said stop means out of said sheet entrance path in re sponse to a signal from said sensing means indicating that said sheet processing apparatus is prepared to receive a sheet and into said sheet entrance mouth in response to a signal from said sensing means indicating that a leading edge is beyond said shoulder surface.

3. A sheet-feed control mechanism as claimed in claim 2 wherein said sheet processing apparatus includes a pair of opposing rollers positioned downstream of said shoulder surface and wherein said sensing means senses the presence of sheets at the nip of said roller pair with said motivating means moving said stop means out of said sheet entrance path when said sensing means does not sense the presence of a sheet at said roller nip and moving said stop means into said sheet entrance path when said sensing means senses the presence of a sheet at said roller nip.

4. A sheet-feed control mechanism as claimed in claim 3 wherein said stop means comprises a rotatable shaft having stop elements affixed thereon for rotation S 6 therewith. a snlcnuid for rutating said shaft tn causc nnid is not energized. said stop clcnicnts' t mun. out 01' said shcct cntrancc S. A sheet-feed control mechanism as claimed in path and a spring attached in said shaft fur rotating said claim 4 wherein said sheet processing apparatus is a shaft In cause said stup clcmcnts tn nimc into said copying machine.

shcct cntrancc path tuward said notch ahcn said snlc- 5 (all 

1. A sheet-feed control mechanism to be used with a sheet processing apparatus which is designed to accept one sheet at a time and which cannot accept a subsequent sheet until a previous sheet has been processed to a predetermined degree, said sheet feed control mechanism comprising: a guide means for defining a sheet entrance path and for guiding sheets inserted into said sheet processing apparatus along said sheet entrance path, said guide means defining a shoulder surface laterally dispOsed to said sheet entrance path and facing the direction from which sheets are inserted into said sheet entrance path; a movable stop means positioned adjacent said sheet entrance path opposite said shoulder surface, said movable stop means being selectively movable into said sheet entrance path for directing the leading edges of sheets thereafter inserted into said sheet entrance path against said shoulder surface but for allowing a previously inserted sheet to continue to move beyond said shoulder surface, and movable out of said sheet entrance path for allowing sheets to pass said shoulder surface without the leading edge thereof being directed toward said shoulder surface; a sensing means for sensing the position of sheets traveling along said sheet entrance path; a motivating means coupled to said sensing means for selectively moving said stop means into and out of said sheet entrance path in response to said sensing means sensing the locations of said sheets.
 2. A sheet-feed control mechanism as claimed in claim 1 wherein: said sensing means is positioned downstream of said shoulder surface for sensing when a sheet has entered said sheet processing apparatus to a predetermined extent at which said sheet processing apparatus is prepared to receive an additional sheet and for sensing when the leading edge of a sheet is beyond said shoulder surface; and said motivating means is for selectively moving said stop means out of said sheet entrance path in response to a signal from said sensing means indicating that said sheet processing apparatus is prepared to receive a sheet and into said sheet entrance mouth in response to a signal from said sensing means indicating that a leading edge is beyond said shoulder surface.
 3. A sheet-feed control mechanism as claimed in claim 2 wherein said sheet processing apparatus includes a pair of opposing rollers positioned downstream of said shoulder surface and wherein said sensing means senses the presence of sheets at the nip of said roller pair with said motivating means moving said stop means out of said sheet entrance path when said sensing means does not sense the presence of a sheet at said roller nip and moving said stop means into said sheet entrance path when said sensing means senses the presence of a sheet at said roller nip.
 4. A sheet-feed control mechanism as claimed in claim 3 wherein said stop means comprises a rotatable shaft having stop elements affixed thereon for rotation therewith, a solenoid for rotating said shaft to cause said stop elements to move out of said sheet entrance path and a spring attached to said shaft for rotating said shaft to cause said stop elements to move into said sheet entrance path toward said notch when said solenoid is not energized.
 5. A sheet-feed control mechanism as claimed in claim 4 wherein said sheet processing apparatus is a copying machine. 